Needle-free injection systems and devices provide an alternative to standard fluid delivery systems, which generally use a needle adapted to penetrate the outer surface of a target. Typically, needle-free injection systems and devices are designed to eject the fluid from a fluid chamber with sufficient pressure to allow the fluid to penetrate the target to the desired degree. For example, common applications for needle-free injection systems and devices include delivering intradermal, subcutaneous and intramuscular injections into or through a recipient's skin. For each of these applications, the fluid must be ejected from the system or device with sufficient pressure to allow the fluid to penetrate the tough exterior dermal layers of the recipient's skin.
Examples of needle-free injection systems and components therefor are disclosed in U.S. Pat. Nos. 4,940,460; 4,941,880; 5,064,413; 5,383,851; 5,399,163; 5,505,697; 5,520,639; 5,746,714; 5,782,802; 5,891,086; 5,893,397; 5,993,412; 6,096,002; 6,132,395; 6,174,304; 6,251,091; 6,264,629; 6,280,410; 6,319,224; 6,383,168; 6,471,669; 6,554,818; 6,572,581; 6,585,685; 6,607,510; 6,620,135; 6,641,554; 6,645,170; 6,648,850; 6,676,630; 6,689,093; 6,752,780; 6,752,781; 6,783,509; 6,935,384; and 6,964,650; U.S. Pat. App. Pub. Nos. 2001/0051793; 2004/0254526; 2006/0089595; 2006/0189927; 2006/02475733; and U.S. patent application Ser. No. 11/539,585, which was filed Oct. 6, 2006, and titled “TRIGGERING MECHANISM FOR NEEDLE-FREE INJECTOR.” The disclosures of these and all other publications referenced herein are incorporated by reference in their entirety for all purposes.